I am a fan of x86_64 as wired-only router, it has the performance to serve even high-speed WAN connections (up to 2.5 GBit/s easily, 10, 20, 40, 100 GBit/s possible), isn't that expensive in comparison and just works.
But I recommend against making x86_64 an AP.
Yes, you can do it
- if you say bye to the the small form-factor (pretty much anything <µATX does not have enough PCIe slots for 2, 3 WLAN cards)
- these cards tend to be off-spec, needing 10+ watts on 3.3 volts (not all mainboards can deliver that and/ or will burn out while trying)
- these cards are running hot, make sure to sort out the cooling (passively and actively)
- if you accept that the PCIe/ M.2 cards cost more than a good plastic wifi router
- if you accept that the pigtails (4-8 needed) and antennas (4-8 needed) cost quite some money and may be of questionable quality
- if you accept that adding many (4-8) antennas to a big µATX sized chunk of metal is not quite the best idea from an rf point of view
- if you manage to spatially distribute them on the case in a way not to break Mu-MIMO too much
If you want to do driver/ kernel development or wifi research, that is the way to go (the price is sadly accordingly, primarily because you need multiple of all components and may have to find the best solution/ buy multiple times), if you 'just' want modern wifi at home, a cheap dedicated plastic AP (running OpenWrt) is a more sensible and likely even 'better' choice.
What AP to choose depends on your requirements and budget, there are good options ranging from the ax3000t, over the dl-wrx36, up to the gl-mt6000 - and there are quite a few options beyond those.
A good alderlake-n/ n100 system with 4* 2.5GBASE-T costs around 100-250 EUR delivered.
A decent to good AP ranges between 27-160 EUR; in typical households, two cheaper APs (with a wired backhaul) beat one high-end AP easily.
Obviously the sky is the limit for either of those.